TAMPA, Fla. (AP) — A 17-ton haul of silver coins, lost for two centuries in the wreck of a sunken Spanish galleon, began its journey back to its home country on Friday after the deep-sea explorers who lifted it to the surface lost their claim to ownership.

Two Spanish military C-130 cargo planes took off after noon from a Florida Air Force base with 594,000 silver coins and other artifacts aboard. They were packed into the same white plastic buckets in which they were brought to the U.S. by Tampa, Fla.-based Odyssey Marine Exploration in May 2007.

“These are emotional and moving moments for me and all my colleagues behind me,” Spain’s ambassador to the United States, Jorge Dezcallar de Mazar, said Friday. He stood on the windy tarmac at MacDill Air Force base, flanked by an entourage of more than two dozen Spanish officials and others.

“History will make us who we are, and today we are witnessing a journey that started 200 years ago,” he said. “This is not money. This is historical heritage.”

The planes were expected to make two refueling stops and land about 24 hours later at one of two air force bases in Madrid in a high-security operation.

Odyssey made an international splash when it discovered the wreck, believed to be the Nuestra Senora de las Mercedes, off Portugal’s Atlantic coast near the Straits of Gibraltar. At the time, the coins were estimated to be worth as much as $500 million to collectors, which would have made it the richest shipwreck haul in history.

The Mercedes was believed to have had 200 people aboard when it was sunk in 1804.

Spain went ahead with transporting the treasure despite a last-ditch, longshot claim to the treasure by Peru.

On Thursday, the Peruvian government made an emergency appeal to the U.S. Supreme Court seeking to block transfer of the treasure to give that nation more time to make arguments in federal court about its claim to being the rightful owner. But that appeal was denied Friday by Justice Clarence Thomas.

Peru had argued the gold and silver was mined, refined and minted in that country, which at the time was part of the Spanish empire.

U.S. courts had previously rejected claims by descendants of the Peruvian merchants who had owned the coins aboard the Mercedes.

Peru’s ambassador to the United States, Harold Forsyth, said the nation would seek redress in Spain via diplomatic channels.

“The ship departed from the port of Callao (adjacent Lima) with a cargo of coins minted in Peru, extracted from Peruvian mines with arms and sweat of Peruvians,” he said.

Peru did not gain its independence until 1824, but its lawyers have argued that it was more than a simple colony, being the local seat of the Spanish crown, when the treasure-laden ship was sunk two decades earlier.

Peruvian cultural authorities say their country’s legal case would have been stronger if it had signed the 2001 U.N. Convention on the Protection of the Underwater Cultural Heritage, which states that countries of origin have priority in deciding the fate of cultural artifacts found in shipwrecks.

Odyssey — which uses a remote-controlled submersible to explore the depths and bring the tiniest of items to the surface — had previously argued that it was entitled to all or most of the treasure. The Spanish government filed a claim in U.S. District Court soon after the coins were flown back to Tampa, contending that it never relinquished ownership of the ship or its contents. A federal district court first ruled in 2009 that the U.S. courts didn’t have jurisdiction, and ordered the treasure returned.

Odyssey had argued that the wreck was never positively identified as the Mercedes. And if it was that vessel, the company contended, then the ship was on a commercial trade trip — not a sovereign mission — at the time it sank, meaning Spain would have no firm claim to the cargo. International treaties generally hold that warships sunk in battle are protected from treasure seekers.

Odyssey lost every round in federal courts trying to hold on to the treasure, as the Spanish government painted them as modern-day pirates plundering the nation’s cultural heritage.

The company has blamed politics for the courts’ decisions since the U.S. government publicly backed Spain’s efforts to get the treasure returned. In several projects since then, Odyssey has worked with the British government on efforts to salvage that nation’s sunken ships, with agreements to share what it recovers. Company officials said the ruling against them may lead to other deep-sea explorers refusing to share information about their claims with governments. They declined to comment further Friday.

Odyssey has said in earnings statements that it has spent $2.6 million salvaging, transporting, storing and conserving the treasure. But it is not expected to receive any compensation from the Spanish government for recovering it because the European nation has maintained that the company should not have tried to do so in the first place.

“I would expect that the companies would respect historical heritage and respect the law of the sea,” Dezcallar de Mazar said. “And the law of the sea states that no matter how (much) times goes by, a sunken man-of-war belongs to the flag.”

In Madrid, the Spanish Culture Ministry recently said the coins are classified as national heritage and must stay inside that country, where they will be exhibited in one or more Spanish museums. It ruled out the idea of the treasure being sold to ease Spain’s national debt in a country grappling with a 23 percent jobless rate and a stagnant economy.